Machine for generating toric surfaces



Sept. 3, 1968 c. M. HODSON MACHINE FOR GENERATING TORIC SURFACES 7Sheets-Sheet 1 Filed May 12, 1965 INVENTOR. CARY M. HODSON f SATTOFTQNEYS Sept. 3, 1968 C. M. HODSON MACHINE FOR GENERATING TORICSURFACES Filed May 12, 1965 (\l 5? LL.

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p 3, 1968 c. M. HODSON 3,399,496

I MACHINE FOR GENERATING TORIC SURFACES I Filed May 12, 1965 7Sheets-Sheet 4 V 1, i l A VII/II IJJLVlI/IA Fig. 6

Sept. 3, 1968 c. M. HODSON MACHINE FOR GENERATING TORIC SURFACES Filedma 12, 1965 7 Sheets-Sheet 5 Sept. 3, 1968 c. M. HODSON MACHINE FORGENERATING TORIC SURFACES '7 Sheets-Sheet 6 Filed May 12, 1965 LS-2 x CR4 c 1OCRA-1 1OCRA 4 R R C m 4 1 M 1 \1 I \l 1 1 5 3 R R 9 C m C m w 1 3Q 5 4 R HI 1 C C I I] 5 P .A J m 2| R 1 pm CA C 6 P 1 M m A 3 #m m R 2 c1 m m 5 2 .H-I m a 19 c m 9 8 P 1968 c. M. HODSON 3,399,496

MACHINE FOR GENERATING TORIC SURFACES Filed May 12, 1965 7 Sheets-Sheet'7 1OCRB-1 LS-l qoc I I I 2CR-3 3CR-2 United States Patent 3,399,496MACHINE FOR GENERATDIG TORIC SURFACES Cary M. Hodson, New Vienna, Ohio,assignor, by mesne assignments, to Textron Inc., Providence, R1, acorporation of Rhode Island Filed May 12, 1965, Ser. No. 455,232 Claims.(Cl. 51-124) ABSTRACT OF THE DISCLOSURE In this generator, the work isswung about an axis perpendicular to the tool axis. The work holder ismounted on an upper slide that is adjustable angularly by a trunnionabout an axis perpendicular to the tool axis. This trunnion is mountedon an intermediate slide carried by a lower trunnion adjustable about anaxis parallel to the axis of the first trunnion. Separate motors drivethe two trunnions and the two slides. Manually adjustable controlsdetermine the positioning of lower trunnion and intermediate slide.Signals from feedback resolvers connected to these two parts determinetheir precise positioning. A member secured to the base holds the upperslide fixed relative to the base while intermediate slide is beingadjusted.

This invention relates to machines for generating toric surfaces andespecially to machines for grinding ophthalmic lenses to produce toricsurfaces thereon.

A toric surface is a surface which has two distinct circular arc curvesin mutually perpendicular reference planes that pass through the surfacein directions normal to the curvature thereof. One of these curves issometimes referred to as the base curve and this term will be usedherein. The other curve is referred to usually as either the cross curveor the cylinder curve, the former being the term to be used herein. Inthe field of optics, these curvatures are expressed in terms ofdiopters, the diopter values of a lens being derived as the value of thereciprocals of the focal lengths of a lens in meters. The base curve isby normal practice the larger radius curve or the curve of smallerdiopter value and the cross curve is of a smaller radius and thereforeof a larger diopter value. In certain special cases the curvatures canbe the same in which event the lens will be spheric rather than toric,but it is understood that in using the term toric surface, these specialcases are also included.

The usual method for generating toric surfaces is to move a lens blankrelative to a cutting tool through an arcuate path in which it contactsagainst a portion of an annular cutting surface on the tool. Forexample, in grinding a lens, a cup shaped wheel is used having anannular surface of arcuate cross section against which the lens blank ismoved while being swung around an arcuate path that passes by theannular edge of the wheel. The lens is held so that its lens axis, thatis the line centrally through the lens and normal to the curvaturesthereof formed by the intersection of the planes in which base and crosscurves are referenced, is held normal to the arcuate path. The radialdistance in the base curve reference plane from the axis of swing to thepoint of tangency of the lens with the annular cutting surface isdeterminative of the base curve. The cross curve is determined by thediameter of the annular cutting surface, normally a constant, and theangle between the lens axis and the axis of rotation of the cutting toolwhen the lens axis passes through the center of arcuate section ofcurvature of the annular cutting surface. The surface so generated canbe either concave or convex and this is dependent upon which side of thecutting surface of the tool it is that the axis of swing in the basecurve refer- 3,399,496 Patented Sept. 3, 1968 ice ence plane is located.A good discussion of the generation of these toric lenses is found inU.S. Patent 2,589,- 488, issued Mar. 18, 1952, on an application by W.D. Fowler.

Toric surface generators are most commonly used in optical shops whereophthalmic lenses are ground in accordance with prescriptions. Seldomare two lenses of the same shape ground in succession and it istherefore common to find that each grinding machine or curve generatoris cutting only a fraction of the time during a working day since eachworkpiece requires a change in set-up. This also means that the machineoperator spends a high proportion of his time setting up his machine.The complicated arrangement of machine slides and adjustable memberstogether with the clamps for securing relatively adjustable memberstogether in adjusted positions after adjustment that have been known andused heretofore do not readily lend themselves to automatic operationand therefore the grinding of lenses has not yet been satisfactorilyautomated although these operations with their high proportion of set-uptime are the type from which the most benefit can be derived byautomation.

It is therefore an object of this invention to provide a toric surfacegenerating machine which is readily adapted for automatic and poweroperation.

It is also an object of this invention to provide a toric surfacegenerator by which adjustment for cross and base curves can beaccomplished accurately by power driven mechanisms.

Yet another object of this invention is to provide a compact machinerequiring very little space but having a relatively wide range ofadjustment.

Another object of this invention is the provision of a completelyautomated toric surface generator.

It is also an object of this invention to provide a toric surfacegenerator in which data can be preset and thereafter used in anautomatic cycle to set-up the machine and to generate a toric surface inaccordance with the preset data.

A further object of this invention is to reduce the amount of timerequired of the operator for set-up and subsequent use of a toricsurface generating machine to free the operator for multiple machinecontrol.

Other objects and advantages of the present invention should be readilyapparent by reference to the following specification, considered inconjunction with the accompanying drawings forming a part thereof, andit is to be understood that any modifications may be made in the exactstructural details there shown and described, within the scope of theappended claims, without departing from or exceeding the spirit of theinvention.

Briefly, this invention provides a toric surface generating machine inwhich a work holding member and tool are relatively swung about an axisthat is perpendicular to the axis of rotation of the tool. The tool hasan annular cutting surface and the relative swing of the work holder andtool causes a workpiece mounted on the tool holder to be moved around anarcuate path in contact with the annular cutting surface. The axis ofrelative rotation of the work holding member and tool is positionable incoordinate directions so as to provide both base and cross curveadjustments, the construction being such that powered movements areeasily achieved. Therefore, present input data stores are includ-able inthe mechanism to provide signal outputs representative of the coordinateposition of the axis of work holder swing. Motors are operated inresponse to these signals to make the coordinate adjustments for setupand when the machine is in its set-up condition, a further power sourceis provided to swing the work holder about its axis. A clearunderstanding of the invention can be obtained from the followingdetailed description in which reference is made to the attached drawingswherein:

FIG. 1 is a front elevational view, partly in section, of a toric lensgrinding machine constructed in accordance with this invention.

FIG. 2 is a sectional view of the machine of FIG. 1 as viewed from line2--2 thereof.

FIG. 3 is a sectional view of the machine taken along line 33 of FIG. 2.

FIG. 4 is a section of the machine as viewed from line 44 of FIG. 3.

FIGS. 5 and 6 are section views of FIG. 3 taken along lines 5-5 and 6-6,respectively, thereof.

FIG. 7 is a section of the mechanism as viewed along the line 7--7 ofFIG. 1.

FIG. 8 is a section view of the portion of the mechanism shown in FIG. 7as viewed on line 8-8.

FIG. 9 is a section of a portion of the mechanism as viewed on line 99of FIG. 1.

FIG. 10 is a section of the machine taken along line 1010 of FIG. 3.

FIG. 11 is a partial view in elevation of a control panel included inthe base of the machine shown in FIG. 1.

FIG. 12 is a section view of the portion of the control panel shown inFIG. 11 and taken along line 12-12.

FIGS. 13a and 13b are schematic electrical control circuit diagrams foroperation of the machine shown in the above listed figures.

FIG, 14 is a partial view of a lens thickness dial as viewed from line14-14 of FIG. 4.

The overall layout and configuration of a lens grinding machineconstructed in accordance with this invention is shown in FIG. 1. Themachine includes a base member 15 which houses and supports the variouselements of the mechanism. A spindle motor M-5 is attached atop the base15 and when energized, operates to rotate a grinding wheel spindlemechanism 17 (FIG. 2) to which it is connected by a drive belt 18 andwhich is enclosed in a spindle housing 19 also received on top of thebase 15. The spindle housing 19 has a work enclosure 20 attached at oneend and in which the cup shaped grinding wheel 21. (FIG. 3) is enclosed.The grinding wheel 21 is fixed in the end of the spindle mechanism 17enclosed in the housing 19 and is rotated at a high rate of speed by themotor M-5 on an axis fixed relative to the base 15. The enclosure 20 isrequired since cutting fluids are used during a grinding operation andsince glass lenses are normally ground with diamond abrasive. Theenclosure 20 isolates the fluid and grinding swarf both for machine andoperator protection. Grinding wheel spindles and work enclosures forlens grinding operations are well known and any of the specificstructures common in the art can be adapted for use on the base 15 inthe positions of the units 19 and 20. The previously cited Patent 2,589,- 488 shows and describes a satisfactory spindle and work enclosuremechanism. Therefore further detail of these units will not beundertaken herein except where necessary in connection with othermechanisms to be described in following passages herein.

Lenses to be ground are mounted on a work holding unit 22 that extendsinto the enclosure 20 where the lens blank 23 (FIGS. 2, 3) is held in aposition adjacent to the grinding wheel 21. The work holding unit 22 issupported on an upper or work slide 24 which in turn is supported on anupper trunnion member 25. The upper trunnion 25 is supported on anintermediate slide 26 for rotation on an axis that extends in adirection perpendicular to the direction of the fixed axis of rotationof the spindle 17 and grinding wheel 21. The intermediate slide 26 issupported in turn on a lower trunnion 27 that is rotatably supported onthe base 15. This describes generally the machine arrangement and themajor units of the machine. The details of machine construction and itsmanner of operation are included in the description to follow.

The lower trunnion 27 is mounted directly on the base of the machine asshown in FIG. 1. The lower trunnion includes a spindle 28 extendingdownward therefrom and fixed securely thereto by machine screws 29,there being only one shown for simplicity. The spindle 28 extends into ahousing 30 that is fixed in place in the base 15 by machine screws 31 toform an integral part of the base 15. A pair of tapered roller bearings32, 33 are received in the housing 30 and these support the spindle 28and trunnion 27 for rotation on the base at a fixed location, this axisof rotation being parallel to the axis of rotation of the upper trunnion25 to be described in detail later herein. A motor M-l is supported inthe base 15 on a fixed mounting bracket 35 to provide power for rotationor angular movement of the lower trunnion 27 on the base 15. The motorM-1 is connected by means of a gearing unit 36 and shaft 37 to a gearedspeed reducer unit 38. The reducer unit 38 has an output shaft 39including a coupling element 40 by which it is connected directly to thelower end of the spindle 28. Thus, the motor M-l is connected to furnishpower for angular movement of the lower trunnion 27 on the base 15. Theshaft 39 of the reducer unit 38 has an electrical resolver 41 connectedto its end opposite the spindle 28 to provide an electrical signal thatis a direct analog of the angular position of the shaft 39 and spindle28 in a well known manner.

The intermediate slide 26 is supported on the lower trunnion 27 formovement relative thereto in a direction transverse to the axis ofangular movement of the trunnion 27. The structure permitting thismovement is shown in FIGS. 1, 3 and 4. A pair of round bar slide ways42, 43 are supported directly on the trunnion 27 and are held in theirrelative parallel positions by screws 44. The ways 42, 43 extend in adirection perpendicular to the axis of the trunnion 27. The intermediateslide has a set of four sliding feet 45-48 that extend downward and overthe slide ways 42, 43 and each of these feet includes an arcuate shoe 49held in place by screws 50, 51, such as is shown for the foot 45, FIG.4, and these shoes 49 provide a wear resistant sliding surface tocontact against the ways 42, 43. The intermediate slide 27 has a motorM-3 supported thereon and this motor M-3 drives a lead screw 53 throughengagement of a pair of bevel gears 54, 55 in a gear box 56, these gearsbeing fixed on the motor output shaft 57 and the screw 53, respectively.The screw 53 is engaged through a nut 58 that is secured to the bottomof the slide 27 between the feet 46, 48 so that as the motor M3 isenergized to rotate the screw 53, the intermediate slide 26 is movedalong the ways 42, 43.

An electrical resolver 59, FIG. 9, is provided in the mechanism toproduce an analog signal representative of the position of the slide 26along the ways 42, 43. A worm shaft 60 extends from the end of the screw53 and through a gear box 61 attached at one end of the slide 26. Theshaft 60 carries a worm 62 that engages with a gear 63 which is fixedonto the rotor shaft 64 of the resolver 59. The resolver 59 is fixed inplace in the gear box 61 by screws 52. Therefore when the lead screw 53.is rotated to move the slide 26, the resolver rotor shaft 64 will beturned correspondingly to alter the resolver analog output signal by anamount proportional to the extent of movement of the slide 26.

The upper trunnion 25 is supported directly by the intermediate slide26, the structure'being shown best in FIGS. 3 and 4. The upper trunnion25 is rotatably supported on the slide 26 by means of a large angularcontact ball bearing 65 embraced therebetween. A stub shaft 66 iscentrally located on the bottom of the trunnion 25 and secured in'placeby screws 67. The lower end of the shaft 66 is received in a taperedroller bearing 68 held in place between the shaft 66 and the slide 26 bya nut 69 threaded onto the shaft 66. A worm gear member 70 is alsoreceived on the shaft 66 and axially located in the proper position byjack-screws 71. The gear member 70 is rotatable relative to the shaft66, not being keyed thereto in any manner. The worm gear 70 does have apin 72, FIGS. 5, 6, fixed therein and which extends upward into a recess73 in the upper trunnion 25. The pin 72 is embraced between adjustingscrews 74, 75 threaded into plungers 76, 77 slidably held in the uppertrunnion and urged toward the pin 72 by springs 78, 79, respectively.This construction provides a firm but resilient driving connection fromthe worm gear and the upper trunnion '25.

The worm gear 70 is engaged by a worm 80, FIGS. 3, 4, that is fixed on ashaft 81 rotatably supported in the intermediate slide 26 for rotationby bearings 82, 83, and 84. The shaft 81 is connected through a couplingsleeve 85 to the output shaft 86 of a geared motor unit M-2. Theresilient connection between the worm gear 70 and upper trunnion 25described previously is provided in the machine to prevent sudden shockfrom the upper trunnions engagement with a fixed stop limiting the arcof grinding motion from damaging the geared motor unit M-2. The shaft 81is adapted at its one end 88 for drive by a crank (not shown) uponrelease of the sleeve 85 from the shaft 81, the release being effectedby removal of a set screw 89.

The upper slide 24 is slidably received on the .upper trunnion 25 toallow relative movement of these two members along a direction in aplane perpendicular to the axes of the lower and upper trunnions 27 and25. The upper slide 24 has a pair of round bar ways 90, 91 fixed on itslower side and these are embraced in upper foot members 9295, FIGS. 1,3, 4 and 7, that are secured to the upper slide 24 in a manner similarto that by which the ways 42, 43 are secured to the lower trunnion 27.Each of the feet 92-95, for example the foot 92, FIG. 4, has an arcuatebushing 96 held in place by screws 97, 98 around the way to provide awear resistant surface for sliding contact. The upper slide also has atoothed rack 99 formed along one side, FIGS. 1, 7 which is engaged by apinion 100 that is fixed on the end of a shaft 101. The shaft 101 isjournaled in bearings 102, 103held in a brake housing portion 104 of theupper trunnion 25. The shaft 101 extends into an electric brake unit 105fixed in the housing 104 that is operable to stop and prevent rotationof the shaft 101 in a conventional manner. This, in effect, fixes theupper slide 24 and upper trunnion 25 to prevent relative movement alongthe ways 90, 91.

The brake housing 104 is also furnished with a manually operated braketo control the rotation of the shaft 101. The manual brake is shown bestin FIG. 8 and is comprised of a collar 106 that is received over theshaft 101 between the bearings 102 and 103. There is a key 107 betweenthe shaft 101 and collar 106 so that the two rotate in unison. A bore108 extends through the housing 104 in a direction transverse to theshaft 101 and a portion of the collar 106 is exposed in the bore 108where it is contacted by a pair of braking nuts. 109, that are slidablein the bore 108. The nuts are internally threaded but of opposite handsand a screw 111, having two threads of opposite hands, is engagedthrough the nuts 109, 110. The thread in the nut 109 is larger indiameter than that in the nut 110 to permit assembly. The screw 111 isjournaled for rotation in a bushing 112 fixed in the housing 104 by aset screw 113. A knurled ring 114 is pinned onto the exposed end of thescrew 111 to provide a convenient means for turning the screw and a slot115 is also provided for engagement by other manual driving means shouldthis be required or necessary. It can be seen that rotation of the screw111 in one direction will draw the nuts 109,110 forcefully against thecollar 106 to stop its rotation while rotation of the screw 111 in theother direction will move the nuts 109, 110 away from the collar 106 andpermits its unimpaired rotation. Thus it is that the shaft 101, pinion100 and rack 99 provide means for securely locking the upper slide 24 inplace along the ways 90, 91.

The work holding unit 22 shown best in FIGS. 3 and 4, is received on topof the upper slide and is movable in a fixed stroke movement toward andaway from the grinding wheel to eliminate and provide, alterna'tely, a

clearance between the wheel 21 and lens blank 23. A pair of round barways 116, 117 are fixed on top of the upper slide 24 parallel to theways 90, 91 on the under side of that slide. A set of feet 118-121 areattached beneath the main housing member 122 of the work holding fixture22. The feet'118-121 are similar to the other b'arway engaging feetdescribed previously and each includes an arcuate way engaging bushing123 held in place by screws 124, 125. The unit 22 is moved along theways 116, 117 by a reversible electric geared motor M4 that is fixed toa bracket 127, FIG. 4, extending laterally out from the side thereof.The motor M-4 rotates a coupling unit 128 that is shown in section inFIG. 2. It is comprised of an inner cone 129 and an outer cone 130 heldtogether by pressure of a spring 131. This is in effect a frictionclutch. The outer cone has a pin 132 fixed therein at an eccentriclocation and the pin 132 is received in a slot 133 extending verticallyalong the side of the housing 122.

As the coupling unit 128 is rotated one way and the other, the movementof the eccentric pin 132 causes the unit 22 to be moved one way and theother along the ways 116, 117. The forward position, or grindingposition of the unit 22 is determined by a positive stop 134 fixed tothe slide 24 between the ways 116, 117, FIGS. 3, 4. The positive stop134 is engaged by a dog 135 depending fro-m the housing 122 when theunit 22 is moved toward the grinding wheel 21. The positive stop 134includes a plunger 136 that is moved out toward the dog 135 by a spring137. This plunger 136 is moved into the stop 134 when engaged by the dog135 to compress the spring 137. This provides a cushioning effect on themechanism to prevent damage to the gears of the motor M-4 which mightotherwise occur if the motor were suddenly caused to engage a rigidstop. The friction clutch provided by the inner and outer cones 129, 130further provides protection for the motor M-4.

The work chucking mechanism is supported in the unit 22 and is providedwith adjustability independent of the movement of the unit 22 along theways 116, 117 to facilitate setting for a desired lens thickness. Thechucking mechanism includes a rigid ram 138 that is supported in abushing 139 and held in place by set screws 140, 141, FIG. 3. Thebushing 139 is slidably received through a bore 142 in the housing 122for axial movement only and is biased away from the grinding wheel 21 bya spring 143 that is compressed between the housing 122 and a flangemember 144 secured onto the rearward end of the ram 138 by screws 145.The bushing 139 has a pair of transverse slots 146, 147 and these areengaged by pins 148, 149 of a forked yoke 150. The yoke 150 is supportedon a pin 151 in the housing and swings thereon about an axisperpendicular to the longitudinal axis of the ram 138. The yoke 150includes an arm 152, FIG. 2, in which a nut 153 is pivotally supportedand the nut is threadly engaged by a screw 154. The screw 154 extendsfrom a crank mechanism 155 that is rotatably supported in a fixedposition in the housing 122. Therefore, as the crank 155 and screw 154are rotated, the yoke 150 is caused to swing and the pins 148, 149 causethe bushing 139 to move axially within the housing 122. The purpose ofthe spring 143 is to provide a constant force tending to move the ram138 away from the wheel 21 and thereby maintain the backlash in themechanical system in a corresponding constant condition.

The end of the ram 138 toward the wheel 21 is adapted to hold the lensblank 23 during the grinding operation. The blank 23 is mounted on ablocking unit 156 that is cast directly upon the back of the lens blank23. The block 156 fits snugly into a bushing 157 that is fixed in placein the ram 138 and the bushing. 157 is provided with appropriate seals158, 159 so that an air tight closing of the end of the ram is effected.A vacuum line 160 is connected at the rear of the ram 138, FIG. 2, toproduce a low pressure within the ram 138 that holds the 7 block 156 inplace. The block 156 also has a small center hole through to. the lensblank 23 and a probe 161 extends through it to engage against the backof the lens blank 23. The probe 161 ,is held against the lens 23 by aspring 162, FIG. 2 and also extends out from therea r of the ram 138through a plug 163 where it is contacted by the sensor 164 of a dialindicator 165 mounted on a bracket 166 attached to the housing 122. Thefunction of the dial indicator 165 will be explained more fullylaterherein.

The upper slide 24 is movable on the ways 90, 91 but this relativemovement takes place asa result of the shifting of the intermediatetrunnion 25 and. the intermediate slide 26 in unison between thelowervvays 42, 43 andthe upper ways 90, 91. The upper slide 24 is heldin a fixed position relative to the base 15 while the shifting of the'intermediate slide 26 and upper trunnion is accomplished. For thispurpose, an arm 167 rigidly fixed to the base 15 is provided and the armextends outward over the upper slide 24 and below the work enclosure 20,FIGS. 1, 3 and 7. The arm 167 carries a depending member 168 thatextends downward from the arm 167 toward the slide 24. The lower end ofthe depending member 168 carries a stud 169 that is closely embraced ina slot 170 in a turn-table member 171. The turn-table 171 is rotatablyreceived in needle bearings 172 that are supported directly in the upperslide 24. The upper slide 24 is provided with a pair of plungers 173,174, FIG. 10, that are engaged against a pair of pins 175, 176,respectively, which are fixed in the turn-table 171. Each of theplungers 173, 174 is urged toward the pins 175, 176 by means of a spring177, 178, respectively. As long as the turntable 171 is oriented to betransverse to the ways 90, 91 of the upper slide 24, the forces actingon the turn-table from the Springs 177, 178 are balanced and theturntable 171 tends to remain stationary in the upper slide 24.

The positioning of the upper trunnion 25 and intermediate slide 26 isnormally performed when the upper ways 90, 91 are parallel to the lowerways 42, 43 and while these ways are in axial alignment with the axis ofthe grinding wheel spindle 17. Therefore the arm 167 restrains the upperslide with the slot 170 transverse to those ways as described. However,the upper trunnion axis of rotation is in most cases not in line withthe axis of rotation of the turn-table 171. Therefore, as the upperslide 24 is swung with the upper trunnion 25-, the stud 169 will tracean arcuate path with respect to the upper slide 24. To permit this andsince the arm 167 and stud 169 are rigid with the base 15, theturn-table 171 isrotated against the centering force of the spring 177,178. At the same time, the stud 169 is moved along the slot 170. Theextremes of swinging movement of the upper slide 24 with the uppertrunnion 26 for any given position of the upper trunnion below the upperslide are determined by fixed stops 179, 180 at the ends of the slot.The purpose of the yieldable drive to the upper trunnion through thesprings 78, 79, FIG. 6, previously described, is to prevent damage tothe geared motor drive thereto when the stops 179, 180 are engaged bythe depending stud 169. The turn-table 171 carries an enclosure 181through which the member 168 and stud 1 69 extend and which extends overthe length of the slot 170. The enclosure 181 provides a mountingsurface to which a pair of limit switches LS-4, LS- are attached andpositioned for operation by the member 168 when that member is at oneend or the other of the slot 170. The signals produced by these switchesLS-4, LS-S are used in controlling the automatic machine cycle whichwill be described later herein. Since the turn-table 171 is located at aposition below the grinding station of the machine, it has been providedwith a cover plate 184 that is supported from the member 168. A hearing185 is provided between the plate 184 and the member 168 to provide freerelative rotary movement of the plate 184 with respect to the member168. A flexible pleated boot 186 8 is connected between the plate 184and the upper slide 24 to provide a complete enclosure around and overthe turn-table 171. The bearing is required between the member 168 andplate 184 since the angle of the arm 167 relative to the upper slide 24changes during a swing of the upper slide 24 in a grinding operation anda drag would otherwise result through twisting of the boot 186. i The.grinding machine described is arranged to facilitate completelyautomatic operation to grind a lens in accordance with presetinformation. In FIG. 11 there is shown apartial view of the electricalcontrol cabinet 187 that is attached to the base 15 of the machine. Thecabinet 187 includes two dials 188, 189 for presetting the desired crosscurve and base curve specifications in diopters. The dial mechanisms areshown in cross section in FIG. 12, each being the same as the other inarrangement andoperation. The dial 188 is fixed on the end of a shaft190 that is rotatably received through a bushing 191.'The bushing 191 isfixed in a stiffening plate 192 that is fixed in place in the cabinet187 by screws 193, shown slightly out of position in FIG. 12. The axialposition of the shaft 190 is maintained by a nut 194 that is turned ontothe shaft and against a bearing 195 that in turn is held against theplate 192 and bushing 191. The inner end of the shaft 190 is journaledin a bushing 196 fixed in a rear support plate 197. A pinion 198 isfixed on the shaft 190 and it meshes with a gear 199 that is in turnfixed on the rotor shaft 200 of an electrical resolver 201. The gear 199is a backlash free gear comprised of two halves biased 'by a yieldablemeans such as a spring (not shown) to relatively counter rotate. Gearsof this type are Well known in the instrument gear art. The resolver 201produces an electrical signal output that is directly proportiona] tothe angular position of the dial 188 The dial 189 is similarly connectedto another resolver 202'which produces an electrical output proportionalto the angular position of that dial 189.

The signals from the resolvers 201, 202 are connected electrically inservo control loops that determine the positioning of the lower trunnion27 and the intermediate slide 26, respectively. The final positioning ofthese two members is determined through a comparison of the signals fromthe command resolvers 201, 202, respectively, against the signals fromthe feedback resolvers 41 (FIG. 1) and 59 (FIG. 9) previously describedin accordance with conventional servo-mechanism practice. The dials 188and 189 are each calibrated in two directions from a zero reference toproduce movement of the appropriate members controlled thereby topositionswhere the machine described will be set to grind a lens havingcross and base curves in accordance with the angular position of thedial relative to a scribed reference mark on the face of a ring 203,204, respectively, fixed onto the cabinet around the dials 188, 189. Thelens will be convex or concave inaccordance with the one of the twoscales of each dial used in setting the machine. The convex andconcavescales are indicated as PLUS and MINUS, respectively, on thedials 188, 189. .I The base curve of a lens as generated by the machineis a result of the swing of the upper slide 24 with the upper trunnion25 and is purely arcuate. Therefore there is no error introduced as aresult of any approximation in that curve. Therefore the ring 204 has asingle fixed reference zeroymark thereon. The cross curve is anapproximation, however, since the efiective diameter of the wheel 21always is the same and the different cross curve radii are produced byvarying the approach of the lens blank around the cutting edge. Thisgives a close approximation but the true'curve is elliptical ratherthancircular. The result is a small error such as is discussed in somedetail in the previously cited patent. The ring 203 is provided with twoscales to provide a convenient means to offset of the zero reference oneway and the other in accordance with the base curve diopter setting andthe direction (plus or minus) of that curve. These corrective scales areshown in FIG. 11 and are labelled therein for clarity. In setting thedial 188 to produce a selected cross curve, the appropriate diopterindex mark in the dial 188 would be positioned opposite to thecorrective scale mark, plus or minus, corresponding to the setting madeon the base curve dial 189. The resulting lens would be more nearlycorrect with a minimized elliptical error and less corrective lapping ofthe lens will be required in the post grinding treatment. The relativespacing of the corrective indicia is obtained by plotting the actualcurves obtained and the ideal curves and scaling the correction inaccordance with the difference.

The lens thickness is adjusted by use of the crank 155 and dialindicator 165 which have been described previously. The dial portionassociated with the crank 155 is shown enlarged in FIG. 14. A stationarythickness dial 205 is attached to the side of the housing 122 and isprovided with two marked scales calibrated in millimeters, one forlenses having a plus curvature and one for lenses having a minuscurvature. The back side of each lens blanks has a known sphericalcurvature and the crank 155 is provided with a dial 206 which hasmarkings representative of the range of curvatures of the blanks to beground. In setting the crank to a desired lens thickness, the crank 155is rotated until the mark on the dial representing the curvature of theback face of the particular lens blank is in alignment with the desiredthickness marking on the dial 205. The dial indicator 165 should readzero at this time, but since the crank mechanism is not as precise asdesirable, the crank 155 may require additional small adjustment untilthe indicator is at its zeroed condition. The normal range of lensthicknesses requires multiple rotations of the pointer in the dialindicator 165 and therefore the crank mechanism serves as a revolutioncounter and rough positioning system but final accuracy is dependentupon the dial indicator 165.

The machine is provided with an automatic cycle control system. Thedials 188 and 189 can be preset for a prescribed lens while the machineis in operation on another lens. The thickness crank 155 cannot bepreset however. When the machine has completed its cycle on thepresently chucked lens, it stops. The operator removes that lens andplaces the next lens in the ram 138. The dials 188 and 189 have beenpresent for this next lens. The thickness adjustment, if a change isrequired, can be made now. The operator then initiates the automaticcycle. The upper and lower trunnions 25, 27 are swung to align the ways90, 91 and 42, 43 parallel. The intermediate slide 26 is then shifted toa position corresponding to thte setting of the base curve dial 189.After this is completed, the lower trunnion is swunk in accordance withthe setting of the dial 188. When this is completed, the machine isready to grind. The operator initiates the grinding cycle and the workholding unit 22 is advanced toward the wheel 21. The upper trunnion 25is then swung to move the blank 23 past the wheel in a feed and grindingmovement. After this, unit 22 is then retracted and the cycle iscomplete and the ground lens can be removed. The automatic cycle can berepeated with new settings that have been dialed into the system duringthe actual grinding operation.

The circuit for the control of the machine to produce the describedcycle is shown schematically in FIGS. 13a, 13b. The circuit employssevent limit switches LS1 through LS-7 as signal feedback units toprovide various function signals from the machine. The switch LS-1 shownin FIG. 1 is mounted on the base below the lower trunnion 27 where it isengaged by dogs (not shown) when the trunnion 27 is swung in eitherdirection to the limit of its swing. The switches LS2 and LS-3 are eachmounted on side of the intermediate slide 25 and are located on oppositesides of that slide. The switch LS-2 is shown in FIG. 1 and it isoperated whenever the upper trunnion 25 is swung to a position that iscounterclockwise from the position in which the upper ways 90, 91 areparallel with the lower ways 42, 43. The switch is not operated when theupper ways 90, 91 are swung clockwise due to a clearance 207 formedunder the upper trunnion 25 where the switch LS2 is in contact. Theother switch LS-3 (not shown in FIG. 1) is similarly mounted on the backside of the slide 26 but is operated whenever the ways 90, 91 are swungclockwise from parallel position (as viewed in FIG. 2). The switchesLS-4 and LS-S are mounted, as described previously, on the cover 181over the slot 170 in the turn-table 171 (FIG. 7). These switches LS-4,LS-S are operated whenever the upper slide 24 and upper trunnion 25 areswung to their full counter-clockwise and clockwise positions,respectively. The other switches LS-6, LS7 are mounted, as shown in FIG.3, on the upper slide 24 and are engaged and operated by the dog whenthe work slide unit 22 is retracted and advanced, respectively.

In describing the circuit of FIGS. 13a, 13b, a cycle of operation willbe followed through to detail the relationships of the various circuitelements and their sequence of operation. It is initially assumed that anew set of prescription values have been recorded by selectedpositioning of the dials 188 and 189 and that the previous cycle hasended with the work holding fixture 22 in its retracted position. Thereis an error signal at the intermediate slide error amplifier 208 andwhen such an error exists a signal is applied through a conductor 209 toenergize the relay 11CR. Similarly an error is present in the lowertrunnion error amplifier 210 and a signal is connected to a conductor211 to energize the relay 13CR. Since the work holder 22 is retracted,the limit switch LS-6 is operated and the relay 6CR is also energized.At this point, the machine operator has chucked a new lens blank 23 inthe ram 138 and has set a selector switch 18W in the regular grindposition shown which will produce a clockwise rotation of the uppertrunnion 25 in the grind portion of the cycle. The machine operator nowpresses a set switch 2SW momentarily and a pair of relays IOCRA andltlCRB are energized through contacts 6CR-2 and 13CR-1 or 11CR'1, all ofwhich are now closed. (Note, contacts of relays correspond indesignation to the respective relays with a suffix number to identifyparticular contacts.) A latch is closed parallel to the switch 2SWthrough contacts 10CRA-6 to hold the relays 10CRA, IOCRB energized uponrelease of the switch 2SW. The upper trunnion 25 and lower trunnion 27must correspond in angular position prior to movement of theintermediate slide 26. If it is assumed that the previous cycle wasregular, the upper trunnion is in a position clockwise from the desiredparallel position and the limit switch LS-3 is closed and the relay 3CRis energized. Since the relay 11CR is energized as described, thecontacts 11CR-3 are closed and a circuit is complete from the switch 2SWthrough contacts 11CR-3, 3CR-1, 10CRA-5 and normally closed contactsM2CW-1 of a relay M2CW. (Contacts that are normally closed, that isclosed when the relay is deenergized, are shown throughout like thecontacts MZCW-l.) The relays M2CCW and 12CR are energized at this timeand the contacts M2CCW-3 are closed and the contacts M2CCW- 2 areopened. The contacts M2CW-2 are closed and the motor M-2 is connected toswing the upper trunnion counter-clockwise toward the parallel position.Since the relay 6CR is energized, the feed rate control voltage controlunit 212 is connected to the motor M-2 for rapid operation throughcontacts 6CR-3, 12CR-1 and 6CR-5. This causes the motor M-2 to operateat its fastest rate to move the upper trunnion toward its parallelposition.

If the upper trunnion 25 is positioned counter-clockwise from theparallel position, the limit switch LS-2 is closed and the relay 2CR isenergized. The relays MZCW and 12CR are then energized through a circuitincluding the contacts 2CR-2, 10CRA-3 and MZCCW-l. The

1 1 motor M-2 is then energized through the contacts M2CW3 and MZCCW-Zto cause a reversed drive of the trunnion in the clockwise directiontoward the parallel position.

When the upper. trunnion 25 reaches its parallel position, the switchesLS2 and LS3 are both open and the relays 2CR and 3CR are bothdeenergized. The relays MZCCW and 12CR are deenergized (also M2CW if itis energized instead of MZCCW). The upper trunnion 25 then stops at ornear the parallel position. The yieldable drive connection to the uppertrunnion, previously described, will allow for a slight misalignment.The intermediate slide error amplifier 208 is then connected by way ofrelay contacts 3CR-2, 2CR-3 and CRB2 to output a signal to one or theother of the relays M3L or M3R through contacts M3R-1 or M3L-1,respectively. The relay energized depends upon the direction of movementof the slide 26 required to null the signal from the amplifier 208. Theslide 26 is then driven by the motor M-3 which is energized eitherthrough the contacts M3L-3 and M3R-2 or M3R-3 and M3L-2. When the erroramplifier 208 is nulled and the intermediate slide is positioned, therelay 11CR is deenergized. It should be noted at this point, that thebrake 105 is reset when the relay 11CR is deenergized, the contacts11CR-4 being closed. It should also be pointed out that if either of therelays 2CR or SCR is energized, the contacts 2CR-4 and 3CR-3 are closedand the brake 105 remains set. Therefore the upper trunnion must be inits parallel position before the brake 105 can be released to permitmovement of the intermediate slide 26. The contacts 10CRB-7 provide aholding circuit for the brake 105 after completion of the automaticsetting of the machine.

Simultaneous with the movement of the upper trunnion 25 to its parallelposition and movement of the intermediate slide 26 to its properposition, the lower trunnion 27 is swung to its proper position inaccordance with the setting of the cross curve dial 188. The errorsignal in the amplifier 210 produces a signal that is connected to oneor the other of direction control relays MlCCW and MlCW whenever therelay contacts lflCRB-l are closed. Which of these relays is to beconnected for energizing is dependent upon the direction of movement ofthe lower trunnion 27 required to null the error signal in the amplifier210. The closing of the contacts MICW along with normally closedcontacts M1CCW-2 energizes the motor to operate and swing the trunnionclockwise. If the contacts M1CCW3 are closed in combination withnormally closed contacts MlCW-3, the energization is in the reversesense and the trunnion 27 is swung counterclockwise until the amplifieroutput is nulled. This can be occurring with movement of the uppertrunnion 25 and intermediate slide since these members are supported onthe lower trunnion 27 and are moved relative thereto. When the lowertrunnion 27 is in the preselected position, the output of the amplifier210 is nulled and the relay 13CR is deenergized.

'The machine at this time is set for grinding except for swinging theupper trunnion to an extreme position from which the grinding operationwill proceed. The positioning of the intermediate slide 26 has resultedin the deenergization of the relay 11CR and therefore the contacts11CR-2 are now closed. With the selector 1SW as shown, the relays MZCCWand 120R are energized through the contacts 4CR-4, 10CRA-5 and M2CW-1.The motor M-2 is again energized as before to swing the upper trunnioncounter-clockwise. When the upper trunnion has swung to itscounter-clockwise limit, the switch LS-4 is closed and the relay 4CR isenergized. The circuit to the relays M2CCW and 12CR is opened and themotor M-2 stops. The contacts 4CR-3 are opened and the last parallelcircuit to the relays 10CRA and IOCRB is opened and these aredeenergized.

If the selector switch 18W is in the back grind position,

12 the upper trunnion 25 will be swung to its extreme clockwise positionto complete the set-prior to grinding. The contacts SCR-6 and SCR-5 arethen used in the same manner as the contacts 4CR4 and 4CR-3 but toenergize and deenergize the motor control relay M2CW and the set-uprelays 10CRA and 10CRB. The limit switch LS5 will be closed to energizethe relay SCR instead of the relay 4CR when the set-up is complete.

The machine operator now momentarily closes the switch 3SW and the relayM5-1 is energized. The contacts of MR-l close in a parallel latchcircuit to bypass the switch 3SW. The relay MSR also has contacts (notshown) which close to energize the spindle motor M-5. At this same time,the relay M4F is energized through the limit switch LS7 and contacts9CR-1 and M4-1. The limit switch LS7 is the switch which signals thatthe work holding unit 22 is advanced. Contacts of the relay M4F (notshown) are connected so that the motor M-4 is now energized and the workholder is advanced. When the work holder 22 moves away from itsretracted position to its advanced position, the relay 8CR is energizedthrough contacts of the switch LS-7 and the relay contacts 4CR-1 whichare closed at this time in a normal grinding operation, that is a swingof the upper trunnion 25 from the counter-clockwise extreme in aclockwise direction. The contacts SCR-1 close to latch the relay 8CRenergized and the contacts 8CR-2 close and complete a circuit throughthe contacts SCR-2, 10CRA2 and M2CCW-1 to energize the relays M2CW and12CR. The motor M2 is energized as before except the selector switch 4SWis connected to select a speed of grinding operation since the relay 6CRis deenergized and the contacts 6CR-4 and 6CR-6 are closed and thecontacts 6CR-5 are open. The grinding continues until the trunnion 25has swung to its most clockwise position where the switch LS-S is closedand the relay SCR is energized. The contacts SCR-2 open and the relaysM2CW and 12CR are deenergized. The contacts 5CR-3 are also closed and acircuit is completed to the relay M4R through contacts 6CR-1 and M4F-1.The relay M4R operates contacts (not shown) which reverse the operationof the motor M-4 to retract the work holding unit 22.

In the event that a back grinding cycle has been selected instead of theregular cycle described, the relay SCR is energized at the end of theautomatic set-up and the relay 9CR is then energized after advancementof the work holding unit, that relay being energized through thecontacts 5CR1 and 4CR2. The relay 9CR is latched energized through itscontacts 9CR2. Also, the relays M2CCW and 12CR are energized through thecontacts 9CR-2 and 10CRA-4 and MZCW-l. When the grind is complete, thelimit switch LS4 is closed and the relay 4CR is energized to open thecontacts 4CR-2 and to deenergize the relay 9CR and stop the machine.When the relay 9CR is deenergized, the contacts 9CR-2 open and therelays MZCCW and 12CR are deenergized. When the relay 9CR isdeenergized, the contacts 9CR-3 are closed and the relay M4R is thenenergized through the normally open contacts 2CR-1 and the normallyclosed contacts 6CR-1 and M4F-1. The relay 2CR has become energizedduring the grinding operation with the swing of the upper trunnion 25from its clockwise extreme to its counter-clockwise extreme. The motorM-4 is then energized to retract the work holding unit 22 and when it isfully back, the limit switch LS-6 is operated and the relay 6CR isenergized. The contacts 6CR-1 open and the relay M4R is deenergized themachine now stops and does not function again until the set switch 2SWis again depressed.

: The control circuit is arranged such that when a regular grindingcycle is selected, that is with the switch ISW in the. position shown,the cycle relay SCR is latched energized through its own contacts SCR-1and remains energized until the master stop switch SSW is depressed tointerrupt automatic operation. The depressing of the switch SSW alsoenergizes the retract relay M4R ifthe work holding unit 22 is advancedat this time. With the relay 80R energized its contacts 8CR-3 are closedand at the end of the normal grind the trunnion 25 is in its fullclockwise position and the limit switch LS-S is operated to energize therelay SCR. Therefore the contacts 5CR-4 are also closed, and as soon asthe unit 22 is retracted, the retract signal relay 6CR is energized toclose the contacts 6CR-2. Therefore a circuit parallel across the switch2SW is completed and the set-up cycle is automatically initiated andproceeds as described previously herein except for initiation which doesnot now require the switch ZSW to be closed. The stop switch SSW alsohas contacts which interrupt the set-up cycle if the switch SSW shouldbe depressed during set-up rather than grind.

From the foregoing detailed description it can be seen that a fullyautomated lens grinder has been provided. The machine can be pre-set sothat when oen cycle is complete, it immediately automatically arrangesitself for the next cycle. The mechanism is compact and provides for aunique cooperation between the various elements. It also provides aconvenient mechanism for selecting lens thickness and further providesfor the reduction of elliptical error.

What is claimed is:

1. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) a work slide,

(e) means for supporting and swinging said work slide on an axis ofrotation perpendicular to the axis of 7 tool rotation,

(f) means for shifting the work slide angularly in a plane perpendicularto the axis of rotation thereof to move said work slide axis of rotationin an arcuate V path having a'predetermined radius to a selected angularposition relative to the axis of tool rotation,

(g) means for selectively adjusting the predetermined radius of thearcuate path of movement of the axis of rotation of said work slide,

(h) means for holding said work slide fixed relative to said base whilethe adjustment of said radius is being effected, and

(i) means for holding a workpiece on said work slide to contact saidannular cutting surface and to swing thereagainst when said work slideis swung about the axis of rotation thereof.

' 2. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on a fixed axis relativeto said base,

(d) a work slide,

(e) means for supporting and swinging said work slide on an axis ofrotation perpendicular to the axis of tool rotation,

(f) means for shifting the work slide angularly in a plane perpendicularto the axis of rotation thereof to move said work slide axis of rotationin an arcuate path having a predetermined radius to a selected angularposition relative to the axis of tool rotation,

(g) means for selectively adjusting the predetermined radiusof thearcuate path of movement of the axis of rotation of said work slide,

(h) means for holding said work slide'fixed relative to said base whilethe adjustment of said radius is being 1 effected, i

(i) means for holding a workpiece on said work slide to swing againstsaid annular cutting surface when said work slide is swung about theaxis of rotation thereof, and

. V (j) means for adjusting the depth of penetration of said annularcutting surface into the workpiece on said work slide.

3. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) a work slide,

(e) means for supporting and swinging said work slide onan axis ofrotation perpendicular to the axis of tool rotation,

(f) means for moving said work slide axis of rotation in the directionof said axis of tool rotation to a selected position therealong,

(g) means for holding said work slide in a fixed position relative tosaid base when the axis of rotation thereof is moved in the direction ofthe axis of tool rotation,

(h) means for angularly shifting said work slide and the axis ofrotation thereof about a fixed axis parallel to the work slide axis ofrotation to a selected position after movement of said work slide axisalong the axis of tool rotation, and

(i) means for holding a workpiece on said work slide to contact saidannular cutting surface and to swing thereagainst when said work slideis swung about the axis of rotation thereof.

4. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) an intermediate member,

(e) means for attaching said intermediate member to said base to swingon a fixed axis perpendicular to the axis of rotation of said tool,

(f) a work slide,

(g) means for supporting said work slide on said intermediate member forangular movement on an axis parallel to the axis of swing of saidintermediate member,

(h) means for positioning the axis of angular movement of said workslide at a selected distance from the axis of swing of said intermediatemember,

(i) means for maintaining said work slide in a fixed position relativeto said base when the axis of angular movement of said work slide isbeing moved,

(3') means for swinging said intermediate member to a selected angularposition on said base,

(k) means for angularly moving said work slide about said axis thereof,and

(1) means for holding a workpiece on said work slide to contact saidannular cutting surface during angular movement of said work slide.

5. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(0) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) an intermediate member,

(e) means for attaching said intermediate member to said base to swingon a fixed axis perpendicular to the axis of rotation of said tool,

(f) a work slide,

(g) means for supporting said work slide on said intermediate member forangular movement on an axis in said intermediate member parallel to thefixed'axis of swing thereof,

(h) means for moving said intermediate slide to shift the axis ofangular movement of said work slide to a selected position spaced fromthe fixed axis of swing of said intermediate slide,

(i) means for holding said work slide in a fixed position relative tosaid base when said intermediate slide is moved,

(j) means for swinging said intermediate slide on said fixed axisthereof to angularly position said intermediate slide and shift the axisof angular move- 15 ment of said work slide to a selected angularposition around the fixed axis of said intermediate slide,

(k) means for holding a workpiece on said work slide and adjacent tosaid cutting tool, and

(1) means for swinging said work slide on said axis of angular movementthereof in said intermediate member for movement past said annularcutting surface in an arcuate path to carry the workpiece held thereoninto contact with said annular cutting surface.

6. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(0) means for supporting and rotating said tool on an axis fixedrelative to said base,

((1) a work slide,

(e) an intermediate slide,

(f) means for connecting said work slide onto said intermediate slidefor rotation on an axis therein perpendicular to the axis of rotation ofsaid tool and for transverse movement relative to said axis of workslide rotation,

(g) means for connecting said intermediate slide onto said base forrotation on a fixed axis parallel to said axis of work slide rotationand for transverse movement relative thereto,

(h) means for shifting said intermediate slide transversely on said baseto a selected location,

(i) means for holding said work slide in a fixed position relative tosaid base when said intermediate slide is shifted transversely on saidbase to effect a corresponding transverse shift of said axis of workslide rotation relative to said work slide,

(j) means for angularly swinging said intermediate slide on said base toa selected angular position relative thereto to effect a correspondingangular positioning of said axis of work slide rotation around the fixedaxis of intermediate slide rotation, and

(k) means for swinging said work slide on said axis thereof in saidintermediate slide for movement in an arcuate path past said annularcutting surface.

7. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(0) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) a work slide,

(e) an intermediate slide,

(f) means for connecting said work slide onto said intermediate slidefor rotation on an axis therein perpendicular to the axis of rotation ofsaid tool and for transverse movement relative to said axis of workslide rotation,

(g) means for connecting said intermediate slide onto said base forrotation on a fixed axis parallel to said axis of work slide rotationand for transverse movement relative thereto,

(h) a first motor connected to said intermediate slide and operable whenenergized to move said intermediate slide transversely relative to saidbase,

(i) means for holding said work slide in a fixed position relative tosaid base when said intermediate slide is moved transversely,

(j) a second motor connected to said intermediate slide and operablewhen energized to swing said intermediate slide around said fixed axisof rotation thereof,

(k) a third motor connected to said work slide and operable whenenergized to swing said work slide around the axis of rotation thereof,and

(1) means for selectively energizing said motors in a predeterminedsequence to adjust the position of said axis of work slide rotation andto swing said work slide past said annular cutting surface in a selectedarcuate path.

S. A-toric surface generator comprising:

' (0) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) a first trunnion member received on said base for rotation on afixed axis perpendicular to the axis of rotation of said tool,

(e) an intermediate slide,

(f) means for supporting said intermediate slide on the first trunnionmember for bidirectional movement thereacross perpendicular to the axisof rotation thereof,

(g) a second trunnion member received on said inter mediate slide forrotation on an a'xis'parallel to the axis of rotation of said firsttrunnion member,

(h) a work slide, 7

(i) means for supporting said work slide on the second trunnion memberfor bidirectional movement relative thereto perpendicular to the axis ofrotation thereof,

(j) means for moving ,said intermediate slide to shift the axes of saidfirst and second trunnion members to a selected spacing,

(k) means for holding. said work slide in a fixed position relative tosaid base when said intermediate slide is moved,

(1) means for swinging said first trunnion member to angularly orientsaid intermediate slide in a selected relationship with the axis ofrotation of said tool,

(111) means for swinging said second trunnion member to move saidworkslide past said annular cutting surface in an arcuate path dependentupon the selected distance between the axes of rotation of said firstand second trunnion members and the selected angular orientation of saidintermediate slide, and

(11) means for supporting a workpiece on said work slide to contact theannular cutting surface during a position of the swing of said secondtrunnion.

9. A toric surface generator comprising:

(a) a base,

(b) a tool having anannular cutting surface,

(0) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) a first trunnion member received on said base for rotation on afixed axis perpendicularto the axis of rotation of said tool,

(e) an intermediate slide,

(f) means for supporting said intermediate slide on the first trunnionmember for bidirectional movement thereacross perpendicular to the axisof rotation thereof, a

(g) a second trunnion member received on said intermediate slide forrotation on an axis parallel to the axis of rotation of said firsttrunnion member,

(h) a work slide,

(i) means for supporting the work slide on the second trunnion memberfor bidirectional movement relative thereto perpendicular to the axis ofrotation thereof,

(j) means for moving said intermediate slide to shift the axes ofsaidfirst and second trunnion member to a selected spacing.

(k) means for holding said work slide in a fixed position relative tosaid base when said intermediate slide is moved, t

(1) means for swinging said first 'trunniongmember to angularly orientsaid intermediate slide in a selected relationship with the axis ofrotation of said tool,

(m) means for swinging said second trunnion member to move saidworkslide past said annular cutting surface in an arcuate path,

(n) means'for supporting'a workpiece from a rearward side thereof onsaid work slide to contact the annular cutting surface at a forward sideof the workpiece a portion of the swing of said second trunnion,

() means for determining the location of the rearward side of theworkpiece on said work slide, and

(p) means for shifting the workpiece on said workslide with reference tothe indicated location of the rearward side thereof and relative to saidtool to adjust the depth of penetration of said annular cutting surfaceinto the workpiece on said workslide, thereby determining the thicknessof said workpiece after generation of a toric surface on the forwardside thereof.

10. A toric surface generator comprising:

- (a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) a first trunnion member received on said base for rotation on afixed axis perpendicular to the axis of tool rotation,

(e) an intermediate slide,

(f) means for supporting said intermediate slide on the first trunnionmember for bidirectional movement thereacross perpendicular to the axisof rotation thereof,

(g) a second trunnion member received on said intermediate slide forrotation on an axis parallel to the axis of rotation of said firsttrunnion member,

(h) a work slide,

(i) means for supporting said work slide on the second trunnion memberfor bidirectional movement relative thereto perpendicular to the axis ofrotation thereof,

(j) a first motor on said first trunnion member and connected to saidintermediate slide for movement thereof on said first trunnion member,

(k) a second motor in said base and connected to said first trunnionmember for angular movement thereof,

(1) means for energizing said first motor to shift said intermediateslide and the axis of said second trunnion member to a selected distancefrom the axis of said first trunnion member,

(m) means for maintaining said work slide in a fixed position relativeto said base when said intermediate slide is shifted on said firsttrunnion member,

(11) means for energizing said second motor to selectively adjust theangular position of said first trunnion member and swing saidintermediate slide to a selected angular position,

(0) a third motor on said intermediate slide and connected to saidsecond trunnion for rotation thereof, and

(p) means for energizing said third motor to swing said second trunnionand carry said work slide in an arcuate path past the annular cuttingsurface of said tool after said first trunnion and intermediate slideare selectively positioned.

11. A toric surface generator comprising:

(a) a tool having an annular cutting surface,

(b) means for rotating said tool on a predetermined axis extendingcentrally through the tool,

(c) a work holder,

(d) means for supporting said tool and work holder adjacent to oneanother and for relatively swinging said tool and work holder about anaxis perpendicular to the predetermined axis of rotation of said tool,

(e) means for shifting the axis of relative swing of said tool and workholder angularly and rectilinearly in a direction radial of the axis ofangular shift in a plane perpendicular to the axis of relative swing,

(f) means for producing signals representative of a predeterminedcoordinate location of said axis of relative swing,

(g) means for'energizing said means for shifting said axis of relativeswing in accordance with said signals to move said axis of relativeswing to said predetermined coordinate location, and

(h) means for swinging said work holder and tool relatively when theaxis of relative swing thereof is in said predetermined coordinatelocation to move said workholder in an arcuate path past said annularcutting surface.

12. A toric surface generator comprising:

(a) a tool having an annular cutting surface with fixed dimensions,

(b) means for rotating said tool on a predetermined axis extendingcentrally through the tool,

(c) a work holder,

(d) means for supporting said tool and work holder adjacent to oneanother and for relatively swinging said tool and work holder about anaxis perpendicular to the predetermined axis of rotation of said tool,

(e) a pair of electrical means, each means being presettable relative toa reference position to produce a signal representing a coordinatelocation of said axis of relative swing,

(f) means for shifting the axis of relative swing of said tool andworkholder angularly and radially of the axis of angular shift in aplane perpendicular to the axis of relative swing in response to thesignals produced by said electrical means, and

(g) means for offsetting the reference position of one of saidelectrical means a predetermined amount scaled in accordance with thepresetting of the other electrical means to modify the signal outputfrom said one electrical means to partially compensate for an ellipticalerror resulting from the fixed dimension of said cutting tool annularsurface.

13. A toric surface generator comprising:

(a) a tool having an annular cutting surface,

(b) means for rotating said tool on a predetermined axis extendingcentrally through the tool,

(c) a work slide,

((1) means for supporting said tool and work holder adjacent to oneanother and for relatively swinging said tool and work slide about anaxis perpendicular to the predetermined axis of rotation of said tool,

(e) means for shifting the axis of relative swinging of said tool andwork holder in coordinate directions angularly and radially of the axisof angular shift in a plane perpendicular to the axis of relative swing,

(f) means for producing signals representative of a predeterminedcoordinate location of said axis of relative swing,

(g) means for energizing said means for shifting said axis of relativeswing in accordance with said signals to move said axis of relativeswing to said predetermined coordinate location,

(h) means for holding a workpiece on said work slide to swing againstsaid annular cutting surface when said work slide is swung about theaxis of rotation thereof,

(i) means for adjusting the depth of penetration of said annular cuttingsurface into the workpiece on said work slide, and

(j) means for swinging said workslide and tool relatively when the axisof relative swing thereof is in said predetermined coordinate locationto move the workpiece held thereon in an arcuate path of contact withsaid annular cutting surface.

14. A toric surface generator comprising:

(a) a tool having an annular cutting surface,

(b) means for rotating said tool on a predetermined axis extendingcentrally through the tool,

(c) a work holder,

(d) means for supporting said tool and work holder adjacent to oneanother and for relatively swinging 19 said tool and work holder aboutan axis perpendicular to the predetermined axis of rotation of saidtool,

(e) a presettable base curve store adapted to record base curve data,

(f) a presettable cross curve store adapted to record cross curve data,

(g) means responsive to said base curve store for shifting the axis ofrelative rotation of said tool and work holder to a predeterminedposition along the axis of rotation of said tool corresponding to thedata recorded in said base curve store, and

(h) means responsive to said cross curve store for shifting the axis ofrelative rotation of said tool and work holder angularly about an axisparallel to the axis of relative rotation of said tool and work holderto a predetermined position laterally offset from the axis of rotationof said tool and corresponding to the data recorded in said cross curvestore.

15. A toric surface generator comprising:

(a) a tool having a cutting surface with a fixed annular shape,

(b) means for rotating said tool on a predetermined axis extendingcentrally through the tool,

(c) a work holder,

((1) means for supporting said tool and work holder adjacent to oneanother and for relatively swinging said tool and work holder about anaxis perpendicular to the predetermined axis of rotation of said tool,

(6) a base curve store having a dial presettable relative to a referenceposition to record base curve data,

(f) a cross curve store having a dial presettable relative to areference position to record cross curve data,

(g) means for offsetting the reference position of said cross curvestore dial in accordance with the presetting of the base curve storedial to compensate for an elliptical error resulting from the fixedannular shape of the cutting tool,

(h) means responsive to said base curve store for shifting the axis ofrelative rotation of said tool and work holder rectilinearly to apredetermined position along the axis of rotation of said toolcorresponding to the data recorded in said base curve store, and

(i) means responsive to said cross curve store for shifting the axis ofrelative rotation of said tool and work holder angularly to apredetermined location laterally offset from the axis of rotation ofsaid tool and corresponding to the data recorded in said cross curvestore.

16. A toric surface geenrator comprising:

(a) a tool having an annular cutting surface,

(b) a work holder,

(c) means for supporting said tool for rotation on a predetermined aXisand adjacent to said work holder,

(d) means for supporting said work holder including (1) a trunnion and(2) a compound slide mechanism supporting said trunnion for rotation onan axis perpendicular to the predetermined axis of rotation of saidtool,

(e) a presettable base curve store adapted to record base curve data,

(f) a presettable cross curve store adapted to record cross curve data,

(g) a pair of motors, each motor operatively connected to said compoundslide mechanism,

(h) a first control circuit responsive to said base curve store tooperate one of said motors to move said trunnion along the axis ofrotation of said tool to a position corresponding to data recorded insaid base curve store,

(i) a second control circuit responsive to said cross curve store tooperate the other of said motors to move said trunnion in a directiontransverse to the 20 axis of rotation of said tool to a positioncorresponding to data recorded in said cross curve store, and (j) meansfor holding said tool and work holder in a fixed relative position whensaid one motor is operated to move said trunnion along the axis ofrotation of said tool. 17. A toric surface generator comprising: (a) abase,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) a work slide,

(e) means for supporting and swinging said work slide on an axis ofrotation perpendicular to the axis of tool rotation,

(f) a presettable base curve store adapted to record base curve data andproduce an output signal proportional thereto,

(g) a presettable cross curve store adapted to record base curve dataand produce an output signal proportional thereto,

(h) means for shifting said work slide angularly in a planeperpendicular to the, axis of rotation thereof in response to saidsignal from said cross curve store to move said work slide axis ofrotation in an arcuate path having a predetermined radius to acorresponding lateral position relative to the axis of tool rotation,

(i) means for adjusting the predetermined radius of the arcuate path ofthe axis of rotation of said work slide to a magnitude corresponding tosaid signal from the base curve store and in response thereto,

(j) means for holding said work slide fixed relative to said base whilethe adjustment of said radius is being effected, and

(k) means for holding a workpiece on said work slide to contact saidannular cutting surface and to swing thereagainst when said work slideis swung about the axis of rotation thereof.

18. A generator for producing a toric surface having selected base andcross curve characteristics comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixedrelative to said base,

(d) an intermediate member,

(e) means for attaching said intermediate member to said base to swingon a fixed axis perpendicular to the axis of rotation of said tool,

(f) a work slide,

(g) means for Supporting said work slide on said intermediate member forangular movement on an axis parallel to the axis of swing of saidintermediate member,

(h) a base curve store adapted to produce an output signalrepresentative of the selected base curve,

(i) a cross curve store adapted to produce an output signalrepresentative of the selected cross curve, (j) means for linearlypositioning the axis of angular movement of said work slide at adistance from the axis of swing of said intermediate membercorresponding to said signal from the base curve store,

(k) means for maintaining said work slide in a fixed position relativeto said base when said axis of angular movement of said work slide ismoved,

(1) means for swinging said intermediate member to an angular positionon said base corresponding to said signal from the cross curve store,and

(m) means for moving said work slide about the axis of angular movementthereof when said intermediate member is angularly positioned and saidaxis of angular movement of the work slide is linearly positioned.

19. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixedrelative to said base,

((1) a work slide,

(e) an intermediate slide,

(f) means for connecting said work slide onto said intermediate slide torotate on an axis therein perpendicular to the axis of rotation of saidtool and for transverse movement relative to said axis of work sliderotation,

(g) means for connecting said intermediate slide onto said base forrotation on a fixed axis parallel to said axis of work slide rotationand for transverse movement relative thereto,

(h) means for producing electrical signals representative of apredetermined coordinate location of said axis of work slide rotation,

(i) means for shifting said intermediate slide transversely on said baseto a location corresponding to one of said electrical signals,

(j) means for holding said Work slide in a fixed position relative tosaid base when said intermediate slide is shifted transversely on saidbase to efifect a corresponding transverse shift of said axis of workslide rotation relative to said work slide,

(k) means for angularly swinging said intermediate slide on said base toan angular position corresponding to another of said electrical signalsto position said axis of Work slide rotation around the fixed axis ofintermediate slide rotation, and

(1) means for swinging said work slide on said axis of rotation thereofin said intermediate slide for movement in an arcuate path past saidannular cutting surface after said axis of work slide rotation ispositioned in said predetermined coordinate location.

20. A toric surface generator comp-rising a base,

a tool having an annular cutting surface,

means for supporting and rotating said tool on an axis fixed relative tosaid base,

a work holder,

a first rectilinearly movable slide on which the work holder is mounted,

a support member on which said slide is movable,

a second rectilinearly movable slide on which said support member isadjustable angularly about an axis perpendicular to the axis of thetool,

a second support member on which said second slide is movable, saidsecond support member being adjustable on the base angularly about anaxis parallel to the axis of adjustment of the first support member,

separate motors for rotating said first and second support members andfor reciprocating said first and second slide, respectively,

means for holding said first slide in a fixed position relative to saidbase when said second slide is adjusted, and

means for controlling the movements of said second slide and secondsupport member comprising a manually presettable control for producingan output signal controlling the operation of the motor for driving saidsecond support member,

a manually presettable control for producing an output signalcontrolling the operation of the motor for driving said second slide,and

signal producing means connected to said second support member and tosaid second slide, respectively, for producing feedback signals uponmovement of said second support and said second slide, respectively, andmeans for comparing the signals produced by the last-namedsignal-producing means with the signals produced by the two presetlablecontrols, respectively, to determine precisely the positions of saidsecond support means and said second slide, respectively.

References Cited UNITED STATES PATENTS HAROLD D. WHlTEHEAD, PrimaryExaminerx

